Thermoplastic compositions comprising polyphenylene oxide and styrene resin are well known. Such compositions are described, for example, in U.S. Pat. No. 3,383,435 of Eric P. Cizek, the disclosure of which is incorporated herein by reference.
These compositions exhibit unusually desirable properties which make them useful throughout a broad range of applications. Of particular importance are their high impact strengths. These make them especially useful in the manufacture of molded parts which must be durable.
Notwithstanding these properties, however, means for obtaining still greater improvement have been sought. This search has been directed, in particular, toward the identification of further impact modifiers.